Such methods are routinely used in systems for transmitting data streams that represent audio and/or video stimuli and can therefore convey data representing cinematographic works or teleconferences proceeding in principle in real time, for example.
Because of a background trend producing effects that are apparent in the telecommunications industry in particular, data of various types is conveyed more and more frequently by means of a common infrastructure, usually employing one or more communications networks, for example a main network conforming to the Internet Protocol cooperating with one or more auxiliary networks, which could be networks of radio stations conforming to a third generation telephone protocol, e.g. the UMTS (Universal Mobile Telecommunications system) standard, cable local area networks, e.g. conforming to the Ethernet (IEEE 802.3) standard, or wireless local area networks, for example conforming to the WiFi (IEEE 802.11) standard.
An auxiliary network can be provided in a home by a local area network of a particular type in which an interface device, for example a home gateway, provides an interface between the main and auxiliary networks and is physically connected to a plurality of terminals such as a television receiver, a personal computer, a telephone, possibly a videophone, etc.
In the current state of the art, known interface devices are arranged so that certain terminals known as dedicated terminals are intended to send or receive only one type of data stream, for example a television receiver receives a data stream representing a television program. For that kind of dedicated terminal to be able to receive a data stream of some other type, assuming that it would be more advantageous to use the dedicated terminal to play back the stimulus concerned, an auxiliary network user must, should it be physically possible, set up a branch connection between the dedicated terminal and an initial terminal considered by the user as being less able than the dedicated terminal to play back the stimulus concerned. To return to the example in which the dedicated terminal is a television receiver, the initial terminal could be a videophone with a screen that is small and therefore less advantageous than the screen of the television receiver.
Thus to share a stream between terminals or to transfer a stream from one terminal to another, a user of the auxiliary network must set up a physical connection between those terminals, representing a time and hardware investment and resulting in the presence in their environment of a cable that is generally unattractive, and that must furthermore be present all the time to allow dynamic control of stream sharing or transfer.